Cavity filter for low PIMD using hybrid cap bolt

A cavity filter for low PIMD (passive intermodulation distortion) using a plurality of hybrid cap bolts, comprising:

• a housing having therein a plurality of cavities partitioned by separation walls and an open upper portion;
• an upper plate coupled onto the upper portion of the housing and provided therein with a plurality of tuning bolts;
• a plurality of air blowing work holes formed respectively on the upper plate and outer sidewalls of the housing and corresponding to the plurality of cavities;
• and
• the plurality of hybrid cap bolts formed of different kinds of materials of metal and non-metal so as to be respectively coupled to the plurality of air blowing work holes with a repulsive force against the plurality of air blowing work holes,
• wherein each of the plurality of hybrid cap bolts comprises:
• a main body including a metallic cap section and a metallic body section and being inserted into each of the plurality of air blowing work holes, and
• a coupling thread formed of a dielectric material by injection molding on an outer surface of the main body to surround the metallic body section of the main body and provided on an outside thereof with threads to be coupled to each of the plurality of air blowing work holes to thereby seal the plurality of air blowing work holes, and
• wherein each of the plurality of air blowing work holes comprises a groove part on which the metallic cap section of each of the plurality of hybrid cap bolts is mounted.